Men often talk about women being “crazy.” That can mean a lot of things, but often, it’s just her behavior that comes from her anxiety about losing your investment to other women.
When women start acting “crazy” and accusing you of all manner of debauchery, it can sometimes mean that she’s become attached to you and doesn’t want to lose you, so she wants to know where you are all the time. It can also mean other things, like she cheated and she’s projecting.
In any case, this is pretty normal behavior, and as long as it doesn’t cause problems, you should understand that it’s based on not wanting to lose your attention to a shiny new woman.